I live in an urban area. I was in the military. I go hunting from time to time, rarely though.
Why do you need a specific kind of weapon, with a specific firing mechanism, to shoot boars? Do you think you are going to full auto 50 boars that charge you? The effective range for a weapon on automatic fire is pretty bad. Get a rifle, get to a saveish distance, single fire the fuckers if you have to.
When you see a bunch of boars charging you run bitch! I have, obviously, never been in that situation but if you can't figure that much out by yourself... idk don't go outside, I guess.